For her walk down the aisle at Boone Hall Plantation and Gardens (where The Notebook was filmed) the Gossip Girl starlet, 25, wore a beaded gown featuring a silk tulle bodice and rose-gold embroidery -- custom-designed by Marchesa, with lots and lots of input by Lively.

"Blake has such an innate style," says Georgina Chapman, who heads up the celeb-loved Marchesa brand with Keren Craig.

"I've worked with her so many times and know her so well," Chapman, 36, told Us Weekly Tuesday night at an NYC bash launching Marchesa's collaboration with the NFL. Lively, Chapman raved, "has a very clean sense of fashion . . .she was very involved."

Swapping emotional vows with a Burberry-clad Reynolds, 35, Lively wore custom Christian Louboutin heels during the ceremony and party, held in Cotton Dock, a historic riverside barn (swathed in white muslin), where the reception was also held.

Fashionista-fave Lively "was a creative bride with a clear vision of what she wanted," a source told Us.